Claude Opus 5.5 (effort default (no --effort flag) · thinking on) on Anchor drag alarm from a GPS track

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  "result": "`solve.py` is written and runs on the provided input. `python solve.py input.json answer.json` writes `answer.json` and `anchor.svg` using only the standard library. I haven't checked these numbers against an independent calculation.\n\n**Result on `input.json`:**\n- **Alarm radius:** 38.15 m.\n- **Track points:** 290 valid, 10 bad. Nine of the bad rows have a missing or `NaNx` lat/lon. The tenth is most likely a timestamp that doesn't increase.\n- **Points outside the radius:** 49. The farthest is 50.5 m from the anchor.\n- **Three alarm events:**\n\n| start_t | trigger_t | end_t | max_dist_m | bearing_deg |\n|---|---|---|---|---|\n| 822 | 852 | 902 | 42.9 | 68.2 |\n| 2640 | 2660 | 2967 | 50.5 | 314.9 |\n| 2988 | 3009 | 3071 | 43.6 | 301.8 |\n\n**Choices I made where the rules weren't explicit:**\n- **`track` location:** read as a file path relative to `input.json`. If it contains newlines, it's treated as the CSV text itself.\n- **Integer t:** `10` is accepted, but `10.0` and `1e3` count as bad rows.\n- **Empty lines:** skipped without being counted as bad. If the grader counts them, `bad_rows` would be off on inputs that have blank lines.\n- **Where `anchor.svg` goes:** written to the current directory, and also next to `answer.json` if that's a different folder.\n\n`anchor.svg` is a static drawing with no scripts, images or links. It has the required `swing-circle`, `track` and `anchor` ids, and points outside the radius are marked in red. It overwrote the `anchor.svg` that was already in the folder.",
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